In order to electrically connect an upper surface electrode formed on an upper surface of a semiconductor substrate and an external terminal, a bonding wire is bonded to the upper surface of the upper surface electrode. In the bonded portion on the upper surface electrode, the upper surface electrode and the semiconductor substrate under the bonded portion may in some cases be damaged because of stress generated when bonding wire is bonded. To prevent damage of the upper surface electrode and the semiconductor substrate due to the stress generated in the bonded portion, Japanese Patent Application Publication No. H7-201908 (patent document 1), for example, discloses that a cell region where a semiconductor element is formed and a dummy cell region where a semiconductor element is not formed are mixed, and a bonding wire is bonded to a surface electrode in a portion formed on the upper surface of the dummy cell region. Thereby damage of the cell region can be controlled. According to Japanese Patent Application Publication No. 2002-222826 (patent document 2), thickness of the entire upper surface electrode is increased to relax the stress generated in a bonded portion.